This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 6 |
| 3 | 27 |
| 4 | 116 |
| 5 | 493 |
| 6 | 2090 |
| 7 | 8855 |
| 8 | 37512 |
| 9 | 158905 |
| 10 | 673134 |
| 11 | 2851443 |
| 12 | 12078908 |
| 13 | 51167077 |
| 14 | 216747218 |
| 15 | 918155951 |
| 16 | 3889371024 |
| 17 | 16475640049 |
| 18 | 69791931222 |
| 19 | 295643364939 |
| 20 | 1252365390980 |
| 21 | 5305104928861 |
| 22 | 22472785106426 |
| 23 | 95196245354567 |
| 24 | 403257766524696 |
| 25 | 1708227311453353 |
| 26 | 7236167012338110 |